To prove him wrong, Lisa visits the Springfield Science Museum to find a career to choose. After rejecting several topics, she decides to take up astronomy.

She convinces Homer to buy her a telescope. The town's lights make it difficult to observe the stars and planets, something Professor Frink describes as "light pollution," so she goes up a hill to watch the sky.

At a town meeting, Lisa and astronomer Fink persuade the mayor to turn off outdoor lights. Everyone can enjoy the night sky and the meteor shower. First, people enjoy the stars and the peculiar constellations, but this results in increased crime, so in another town meeting, Mayor Quimby turns the lights back on, so that it's as bright as if it were noon.

Meanwhile, when Bart is being interviewed by Declan, he notices Nelson is popular because he stole a hood ornament from a car. Bart then decides that the only way to be cooler than him is to steal one himself.

Fat Tony is very hostile when his car is touched. Bart has trouble finding a hood ornament, since every car around has been harvested during the time the street lights have been turned off, so he focuses on trying to steal the ornament from Fat Tony's car. This proves to be a challenge once all the street lights are turned on. But Bart isn't the only one suffering from the lights. They're so bright during the night that the entire town can't get to sleep. Lisa is frustrated because she will miss the meteor shower.

Seeing that both Bart and Lisa are looking for the same thing, they work together to get a very drowsy Homer to give them access into the Springfield Nuclear Power Plant. Homer is so suggestible, he is easily convinced he is playing patty cake with Maggie, and he activates the door's hand control. They enter and pull the main power lever to "overload". The lights start to explode everywhere, leading to a mass blackout. The town gathers into a mob which immediately turns peaceful after they look at the meteors.

Bart steals the long-awaited hood ornament from Fat Tony's car.

Professor Frink is nearly hit by a meteor that falls near the observatory that contains some carbon-based molecules, with which he says he may be able to prove the existence of life in outer space, but an alien inside hops away.

Cut to Declan's documentary, in which some kids talk about their desires -- one of which is Milhouse wanting to become a baseball player.